The invention relates to pocket billiards apparatus and methods and particularly to apparatus and methods for positioning the ball rack used to position the balls to start a new game. The term “billiards” as used herein will be understood to refer to the games of billiards, pool, and snooker. More particularly, the rack positions all of the balls, except the cue ball, in an array appropriate for the specific game. For example, the array may be triangular although other games may utilized in array having another shape. For those games utilizing a triangular array, the rack must be positioned so that the ball at the apex of the triangular array nearest to the center of the table is directly on the foot spot. When the balls are racked, all the balls in the array must be lined up behind the apex ball (when present) and pressed together so that adjacent balls are in contact with each other. The positioning of the balls in the racking process affects the break which affects the subsequent play of the game. The reliance on positioning the apex ball on the foot spot has inherent weaknesses. For example, when the apex ball is on top of the foot spot it is not possible to see the foot spot. U.S. Pat. No. 6,609,307, issued on Aug. 26, 2003 to Haynes et al., includes a laser apparatus utilizing a single laser beam for positioning the apex ball. This patent is incorporated herein by reference.
While the apparatus described therein provides some advantage over the mere reliance on a foot spot on the upper face of the table, it still does not ensure the precise placement of all of the other balls within the rack. More specifically, even the apparatus in this patent does not preclude a player from improper alignment of the rack. It is clear that, when using a triangular rack, the side of the rack opposite to the apex ball should ideally be perpendicular to an imaginary line that axially bisects the elongated billiard table. Stated another way, if the rack is optimally positioned, an imaginary line that axially bisects the elongated billiard table will also bisect the rack when the rack is properly positioned. Just as very subtle angular variations produced radical changes in the result produced by given a shot, it is clear that subtle angular variations can produce radical changes when the break shot is made. The placement of a laser apparatus to produce a single spot on the table corresponding to the apex ball is complicated by the very common placement of elongated lighting apparatus over the table and particularly over the portion of the table that includes the conventional foot spot.
United States Patent Application Publication US 2002/0032068 A1, published on Mar. 14, 2002, identifies the problem of the rack not being square with the table. The asserted solution therein utilizes a plurality of light sources including lasers and light emitting diodes or other sources of light together with a plurality of beam splitting elements positioned on the rack and a plurality of photo detectors. At least in some cases the apparatus requires modification of the table as well as the rack. The multiplicity of elements required for alignment will inherently be dependent on each of these multiple elements not being bumped in a manner that would change the alignment. In addition, the location of these elements on the upper face of the table and on the rack increases the probability of these elements be bumped.
U.S. Pat. No. 6,371,860 utilizes laser apparatus to illustrate the position of a foul line.